Viability Test Of Lactic Acid Bacteria And Lactic Acid Content In Few Commercial Probiotic Gels

Probiotic skincare gel is a skincare product containing lactic acid bacteria (LAB), which offers advantages over regular skincare gels, including numerous health benefits for human skin. Generally, probiotics from the lactic acid bacteria (LAB) group are suitable for use in skincare products. The purpose of this study is to evaluate the viability of probiotic skincare gel, as well as to test for the presence of lactic acid bacteria and lactic acid content.This study employs an experimental method. The initial testing involved assessing the viability of LAB using the total plate count (TPC) method to calculate bacterial colonies. Other tests included pH measurement, microscopic and macroscopic bacterial examinations, and lactic acid content analysis using acid-base titration. The results showed that LAB viability tests on samples A, B, C, D, and E over seven consecutive days indicated that the lactic acid bacteria remained alive. Colony counts using the total plate count method for samples A, B, C, and D met the established range criteria of 30–300 for colony counts and 10²–10⁶ CFU/mL, which is considered normal for application on human skin. However, sample E did not meet the criteria. The pH results for samples A, B, D, and E met the standard skin pH range of 4.5–6.5, with respective pH values of 6.1, 5.7, 4.7, and 5.7. Sample C, with a pH of 3.0, fell outside the acceptable skin pH range. Microscopic and macroscopic examinations of samples A, B, C, D, and E revealed characteristics of lactic acid bacteria.The lactic acid content test results for samples A, B, C, D, and E demonstrated the presence of lactic acid, as evidenced by the color change to pink during titration. Based on the findings, it can be concluded that all probiotic skincare gel samples contained viable lactic acid bacteria. Additionally, all samples contained lactic acid, as confirmed by the color change during titration. Colony counts for samples A, B, C, and D met the established range criteria of 30–300 for colony counts and 10²–10⁶ CFU/mL, which is considered appropriate for human skin application.